add links to contributing guide and code (#5006)

Signed-off-by: nikki everett <[email protected]>

docs/flyte_agents/developing_agents.md

@@ -15,7 +15,7 @@ If you need to create a new type of task, we recommend creating a new agent to r
 
 ```{note}
 
-We strongly encourage you to contribute your agent to the Flyte community. To do so, follow the steps in "[Contributing to Flyte](https://docs.flyte.org/en/latest/community/contribute.html)", and reach out to us on [Slack](https://docs.flyte.org/en/latest/community/contribute.html#) if you have any questions.
+We strongly encourage you to contribute your agent to the Flyte community. To do so, follow the steps in "[Contributing to Flyte](https://docs.flyte.org/en/latest/community/contribute.html)" to add your agent to [Flytekit](https://github.com/flyteorg/flytekit/tree/master/plugins) and [create an example](https://docs.flyte.org/en/latest/flytesnacks/contribute.html) of your agent for the [Integrations](https://docs.flyte.org/en/latest/flytesnacks/integrations.html) documentation. If you have any questions, reach out to us on [Slack](https://docs.flyte.org/en/latest/community/contribute.html#).
 
 ```
 
@@ -31,7 +31,7 @@ While agents can be written in any programming language, we currently only suppo
 
 ## Async agent interface specification
 
-To create a new async agent, extend the `AsyncAgentBase` and implement `create`, `get`, and `delete` methods. These methods must be idempotent.
+To create a new async agent, extend the [`AsyncAgentBase`](https://github.com/flyteorg/flytekit/blob/master/flytekit/extend/backend/base_agent.py#L127) class and implement `create`, `get`, and `delete` methods. These methods must be idempotent.
 
 - `create`: This method is used to initiate a new job. Users have the flexibility to use gRPC, REST, or an SDK to create a job.
 - `get`: This method retrieves the job resource (jobID or output literal) associated with the task, such as a BigQuery job ID or Databricks task ID.
@@ -78,7 +78,7 @@ For an example implementation, see the [BigQuery agent](https://github.com/flyte
 
 ## Sync agent interface specification
 
-To create a new sync agent, extend the `SyncAgentBase` class and implement a `do` method. This method must be idempotent.
+To create a new sync agent, extend the [`SyncAgentBase`](https://github.com/flyteorg/flytekit/blob/master/flytekit/extend/backend/base_agent.py#L107) class and implement a `do` method. This method must be idempotent.
 
 - `do`: This method is used to execute the synchronous task, and the worker in Flyte will be blocked until the method returns.